/Engine/Plugins/Animation/ControlRig/Source/ControlRigDeveloper/Public/ControlRigBlueprint.h
Returns the modified event, which can be used to subscribe to topological changes happening within the hierarchy. The event is broadcast only after all hierarchy instances are up to date
The event used for subscription.
[FRigHierarchyModifiedEvent](API\Plugins\ControlRig\Rigs\FRigHierarchyModifiedEvent) & OnHierarchyModified()